Thin film coil and electronic device having the same

ABSTRACT

There are provided a thin film coil and an electronic device having the same, the thin film coil including a substrate; and a coil pattern including a first coil strand and a second coil strand formed on both surfaces of the substrate, respectively, wherein the first coil strand formed on one surface of the substrate includes at least one gyration path that passes through the other surface of the substrate and gyrates.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Ser. No. 13/533,560 filedJun. 26, 2012 which claims the priority of Korean Patent Application No.10-2012-0032341 filed on Mar. 29, 2012, in the Korean IntellectualProperty Office, the disclosures of which are incorporated herein byreference.

BACKGROUND

1. Field

The present disclosure relates to a thin film coil and an electronicdevice having the same, and more particularly, to a contactless powertransfer apparatus capable of wirelessly transmitting power by usingelectromagnetic induction and a thin film coil used therefor.

2. Description of Related Art

Recently, in order to charge a rechargeable battery installed in amobile terminal or the like, a system for wirelessly transmitting power,namely, in a contactless manner, has been under research.

In general, a contactless power transfer apparatus includes acontactless power transmission apparatus transmitting power and acontactless power reception apparatus receiving and storing power.

Such a contactless power transfer apparatus transmits and receives powerby using electromagnetic induction, and to this end, each contactlesspower transfer apparatus includes a coil therein.

A related art contactless power transfer apparatus is configured to havea coil wound parallel to a bottom surface thereof (i.e., an externalcontact surface). Also, a coil may be configured to be fixed to a bottomsurface by an adhesive, a bonding sheet, or the like.

However, in the related art, a general wire-type coil is employed. Thus,coils are wound in an overlapping, stacked manner. This may cause adefect in which the thickness of a contactless power transfer apparatusis increased due to the thickness of the coil and the number of windingsof coils.

Thus, in order to keep up with the recent trend in which relativelythinner devices are preferred, a development of a thinner contactlesspower transfer apparatus is required.

Also, the related art largely uses a single line type coil, so an ACresistance value may be increased due to an eddy current, a skin effect,or the like, at a low frequency, to thereby cause loss.

SUMMARY

According to an aspect a thin film coil formed to be relatively thinnerand an electronic device having the same are provided.

Another aspect provides a contactless power transfer apparatus having asignificantly reduced thickness by using a thin film coil.

Another aspect provides a contactless power transfer apparatus capableof significantly reducing loss caused by an eddy current, a skin effect,or the like, at a low frequency.

According to an aspect, there is provided a thin film coil including: asubstrate; and a coil pattern including a first coil strand and a secondcoil strand formed on both surfaces of the substrate, respectively,wherein the first coil strand formed on one surface of the substrateincludes at least one gyration path that passes through the othersurface of the substrate and gyrates.

The gyration path may share a portion of the second coil strand formedon the other surface of the substrate.

The gyration path may be formed as the first coil strand is connected tothe second coil strand through a gyration via.

The at least one gyration path may include: two gyration viaselectrically connecting the first coil strand and the second coilstrand; and a shared section disposed between the two gyration vias ofthe second coil strand.

The thin film coil may further include: two contact pads disposedoutwardly of the coil pattern and electrically connected to both ends ofthe coil pattern.

One end of the first coil strand may be electrically connected to thecontact pad through a portion of one surface of the substratecorresponding to the gyration path.

The first coil strand and the second coil strand may be connected inparallel.

The second coil strand may include a conductive connection via formed tobe disposed at each of both ends thereof and may be electricallyconnected to the first coil strand by the conductive connection via.

The first coil strand and the second coil strand may be disposed onportions of both surfaces of the substrate to which they correspond in avertical direction.

According to another aspect, there is provided a thin film coilincluding: a substrate; a coil pattern including a first coil strand anda second coil strand formed on both surfaces of the substrate,respectively; and two contact pads disposed outwardly of the coilpattern and electrically connected to both ends thereof, wherein thefirst coil strand formed on one surface of the substrate includes: aspiral pattern; and a lead out pattern disposed to traverse the spiralpattern from one end disposed at an inner side of the spiral pattern soas to be electrically connected to the contact pad.

A portion of the spiral pattern of the first coil strand in which thelead out pattern is disposed may pass through the other surface of thesubstrate and the spiral pattern may gyrate based on the lead outpattern.

The gyrating portion of the first coil may share a portion of the secondcoil strand formed on the other surface of the substrate.

According to another aspect, there is provided an electronic deviceincluding: a contactless power transmission apparatus having a thin filmcoil including a first coil strand and a second coil strand formed onboth surfaces of a substrate and connected in parallel, respectively,the first coil strand formed on one surface of the substrate includingat least one gyration path that passes through the other surface of thesubstrate and gyrates; and a case accommodating the contactless powertransmission apparatus therein.

The contactless power transmission apparatus may be directly attached toan inner surface of the case or disposed to be closer to the innersurface of the case.

The electronic device may further include: a battery storing powergenerated from the contactless power transmission apparatus.

The electronic device may further include: a voltage conversion unitconverting alternating current (AC) power supplied from the outside intoan AC voltage having a particular frequency and providing the convertedAC voltage to the contactless power transmission apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features and other advantages will be moreclearly understood from the following detailed description taken inconjunction with the accompanying drawings, in which:

FIG. 1 is a perspective view schematically illustrating an electronicdevice according to an exemplary embodiment;

FIG. 2 is a cross-sectional view taken along line A-A′ in FIG. 1;

FIG. 3 is an exploded perspective view schematically showing acontactless power reception apparatus of FIG. 2;

FIG. 4 is an exploded cross-sectional view taken along line B-B′ in FIG.3;

FIG. 5 is an assembled cross-sectional view of the contactless powerreception apparatus of FIG. 4;

FIG. 6 is an enlarged partial perspective view showing a portion ‘C’ inFIG. 3;

FIG. 7 is a perspective view showing a lower surface of a thin film coilaccording to an exemplary embodiment;

FIG. 8 is an enlarged partial perspective view showing a portion ‘E’ inFIG. 7;

FIG. 9 is a partial cross-sectional view taken along line D-D′ in FIG.6; and

FIG. 10 is a perspective view schematically showing a thin film coilaccording to another exemplary embodiment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The terms and words used in the present specification and claims shouldnot be interpreted as being limited to typical meanings or dictionarydefinitions, but should be interpreted as having meanings and conceptsrelevant to the technical scope based on the rule according to which aninventor can appropriately define the concept of the term to describemost appropriately the appropriate method he or she knows for carryingout the invention. Therefore, the configurations described in theembodiments and drawings are merely exemplary embodiments but do notrepresent all of the technical spirit. Thus, the application should beconstrued as including all the changes, equivalents, and substitutionsincluded in the spirit and scope of the present disclosure at the timeof filing this application.

Hereinafter, embodiments will be described in detail with reference tothe accompanying drawings. At this time, it is to be noted that likereference numerals denote like elements in appreciating the drawings.Moreover, detailed descriptions related to well-known functions orconfigurations will be ruled out in order not to unnecessarily obscurethe subject matter of the present disclosure. Based on the same reason,it is to be noted that some components shown in the drawings areexaggerated, omitted or schematically illustrated, and the size of eachcomponent does not exactly reflect its actual size.

Hereinafter, embodiments of the present disclosure will be described indetail with reference to the accompanying drawings. In describingexemplary embodiments, a contactless power transfer apparatuscomprehensively refers to a contactless power transmission apparatustransmitting power and a contactless power reception apparatus receivingand storing power.

FIG. 1 is a perspective view schematically illustrating an electronicdevice according to an exemplary embodiment, and FIG. 2 is across-sectional view taken along line A-A′ in FIG. 1.

With reference to FIGS. 1 and 2, an electronic device according to thepresent embodiment may be a portable device 10 or a charging device 20,or may be a contactless power reception apparatus 100, or a contactlesspower transmission apparatus 200 provided in the portable device 10 orthe charging device 20.

The portable device 10 may include a battery 12 and a contactless powerreception apparatus 100 providing power to the battery 12 to charge thebattery 12.

The battery 12 may be a rechargeable battery (or a secondary battery)and may be detachably attached to the portable device 10.

The contactless power reception apparatus 100 may be accommodated withina case 11 of the portable device 10 and directly attached to an innersurface of the case 11 or disposed to be as close as possible to theinner surface of the case 11.

Also, the charging device 20 according to the present embodiment isprovided to charge the battery 12 of the portable device 10. To thisend, the charging device 20 may include the contactless powertransmission device 200 within the case 21.

The charging device 20 may convert household AC power provided from theoutside into DC power, convert the DC power into an AC voltage having aparticular frequency, and provide the converted AC voltage to thecontactless power transmission device 200. To this end, the chargingdevice 20 may include a voltage conversion unit 22 converting householdAC power into an AC voltage of a particular frequency.

When the AC voltage is applied to a thin film coil (not shown) withinthe contactless power transmission device 200, a magnetic field aroundthe thin film coil is changed. Then, a voltage based on the change inthe magnetic field is applied to the contactless power receptionapparatus 100 of the electronic device 10 disposed to be adjacent to thecontactless power transmission device 200, and accordingly, the battery12 is charged.

Hereinafter, the contactless power reception apparatus 100 provided inthe portable device 10 will be described in detail.

FIG. 3 is an exploded perspective view schematically showing acontactless power reception apparatus of FIG. 2. FIG. 4 is an explodedcross-sectional view taken along line B-B′ in FIG. 3. FIG. 5 is anassembled cross-sectional view of the contactless power receptionapparatus of FIG. 4.

With reference to FIGS. 3 through 5, the contactless power receptionapparatus 100 may include a magnetic unit 120 and a thin film coil 110.

The magnetic unit 120 has a flat plate-like shape (or a sheet-likeshape) and is disposed on one surface of the thin film coil 110 andfixedly attached to the thin film coil 110. The magnetic unit 120 isprovided to effectively form a magnetic path of a magnetic fieldgenerated by coil patterns 113 of the thin film coil 110. To this end,the magnetic unit 120 may be formed of a material which is able toeasily form a magnetic path, and specifically, a ferrite sheet may beused as a material of the magnetic unit 120.

However, the magnetic unit 120 is not limited to the foregoingconfiguration. Namely, variable applications maybe implemented; forexample, ferrite powder or a magnetic solution may be applied to onesurface of the thin film coil 110, or the like.

Meanwhile, although not shown, a metal sheet may be further added to anouter surface of the magnetic unit 120 as necessary in order to shieldelectromagnetic waves or leakage magnetic flux. The metal sheet may beformed of aluminum, or the like, but is not limited thereto.

Also, in the contactless power reception apparatus 100 according to thepresent embodiment, a bonding unit 140 may be interposed between thethin film coil 110 and the magnetic unit 120 in order to firmly fix andattach the thin film coil 110 and the magnetic unit 120.

The bonding unit 140 is disposed between the thin film coil 110 and themagnetic unit 120 and bonds the magnetic unit 120 and the thin film coil110. The bonding unit 140 may be formed by a bonding sheet or a bondingtape, or an adhesive or a resin having adhesiveness may be applied to asurface of a substrate 112 or the magnetic unit 120. In this case, thebonding unit 140 may contain ferrite powder to have magnetism, alongwith the magnetic unit 120.

The thin film coil 110 may include the substrate 112 and the coilpatterns 113 formed on the substrate 112.

The substrate 112 of the thin film coil 110 according to the presentembodiment is a thin film substrate, which may be, for example, aflexible printed circuit board (FPCB). However, the substrate is notlimited thereto and any substrate, such as a film, a thin PCB, or thelike, may be variably used, as long as the substrate is relatively thinand is able to form a wiring pattern.

FIG. 6 is an enlarged partial perspective view showing a portion ‘C’ inFIG. 3. FIG. 7 is a perspective view showing a lower surface of a thinfilm coil according to an exemplary embodiment. FIG. 8 is an enlargedpartial perspective view showing a portion ‘E’ in FIG. 7. FIG. 9 is apartial cross-sectional view taken along line D-D′ in FIG. 6.

With reference to FIGS. 6 through 9, the coil patterns 113 according tothe present embodiment are formed as wiring patterns on both surfaces ofthe substrate 112, and may have a spiral shape on the plane formed bythe substrate 112.

The coil patterns 113 may include a plurality of coil strands 117 and118 disposed to be parallel. Here, the respective coil strands 117 and118 maybe connected in parallel to form the single coil pattern 113. Inthe present embodiment, the coil strands 117 and 118 are formed on bothsurfaces of the substrate 112 to form the single coil pattern 113.

In order to connect the coil strands 117 and 118 in parallel, the thinfilm coil 110 according to the present embodiment may include aplurality of conductive connection vias 114. The connection vias 114 mayelectrically connect the coil strands 117 and 118 at both ends of thecoil strands 117 and 118.

As illustrated in FIG. 6, in the present embodiment, a case in which theconnection vias 114 are formed at inner ends of the spiral pattern 117 aand contact pads 119 is taken as an example. However, the vias 114 arenot limited thereto and the connection vias 114 may be formed at variouspositions, have various sizes, and various shapes according to the shapeor structure of the coil pattern 113.

Also, according to the present embodiment, any one (e.g., the first coilstrand 117) of the coil strands 117 and 118 formed on both surfaces ofthe substrate 112 may include a spiral pattern 117 a and a lead outpattern 117 d disposed to traverse the spiral pattern 117 a from one enddisposed within the spiral pattern 117 a.

The lead out pattern 117 d is provided to connect an end of the spiralpattern 117 a to the outside of the coil pattern 113, namely, to thecontact pad 119 as described hereinafter. Thus, the lead out pattern 117d is formed as a pattern electrically connecting the end of the spiralpattern 117 a disposed at the innermost portion and the contact pad 119.

Accordingly, as shown in FIG. 9, the spiral pattern 117 a of the firstcoil strand 117 is formed to gyrate based on the lead out pattern 117 dat the portion in which the lead out pattern 117 d is disposed. Namely,the spiral pattern 117 a of the first coil strand 117 forms at least onegyration path going through the other surface of the substrate 112 inthe portion in which the lead out pattern 117 d is disposed, and thus,the spiral pattern 117 a may maintain the coil shape without beinginterfered with by the lead out pattern 117 d.

The gyration path (not shown) may be formed not to be in contact with acoil strand (hereinafter, referred to as a ‘second coil strand’)disposed on the other surfaces of the substrate 112. In this case, thegyration path may be disposed in a space between the second coil strands118.

In this case, however, the entire area of the thin film coil may beincreased due to the gyration path.

Thus, in the present embodiment, the thin film coil 110 forms thegyration path by using the second coil strand 118. Namely, in thepresent embodiment, the gyration path shares portions of the second coilstrand 118.

As shown in FIGS. 6 through 9, conductive gyration vias 115 are disposedat portions of the spiral pattern 117 a according to the presentembodiment which are discontinued by the lead out pattern 117 d. Thefirst coil strand 117 is electrically connected to the second coilstrand 118 byway of the gyration vias 115.

Thus, in the present embodiment, the single gyration path may includetwo gyration vias 115 and a portion (i.e., a shared section ‘S’ in FIG.9) of the second coil strand 118 disposed between the gyration vias 115.The gyration paths by the number corresponding to the number of windingsof the spiral pattern 117 a may be formed.

Also, in the present embodiment, the first coil strand 117 and thesecond coil strand 118 of the coil pattern 113 are disposed on portionsat which they are mutually projected by the medium of the substrate 112(namely, at positions at which the first coil strand 117 and the secondcoil strand 118 correspond to each other in a vertical direction). Thus,when the gyration via 115 is formed to be perpendicular to the substrate112, the first coil strand 117 and the second coil strand 118 may beeasily electrically connected to mutually corresponding patterns byvirtue of the gyration via 115.

With such a configuration, in the present embodiment, the first andsecond coil strands 117 and 118 of the coil pattern 113 areindependently disposed on both surfaces of the substrate 112 up to aposition in which the lead out pattern 117 d is formed, but at theportion where the lead out pattern 117 d is formed, the second coilstrand 118 on the other surface of the substrate 112 is shared together.

Thus, the coil pattern 113 have a structure in which the respective coilstrands 117 and 118 are electrically connected by the number of windingsof the coil pattern 113 in the middle of the pattern, rather than havinga structure in which the respective coil strands 117 and 118 areelectrically connected only at both ends of the pattern.

Meanwhile, in the present embodiment, a case in which the lead outpattern 117 d is formed at the first coil strand 117 formed on the uppersurface of the substrate 112 is taken as an example. However, lead outpattern is not limited thereto and a lead out pattern maybe formed on alower surface, rather than on an upper surface, of the substrate 112,namely, on the second coil strand 118.

Also, in the present embodiment, a case in which the respective coilstrands 117 and 118 formed on both surfaces of the substrate 112 areformed at positions at which they are mutually projected by the mediumof the substrate 112 is taken as an example, but is not limited thereto.Namely, the respective coil strands 117 and 118 formed on the respectivesurfaces of the substrate 112 may be formed in mutually deviatedpositions, rather than in mutually projected positions, or the like.Namely, the coil strands may be variably applied as necessary. In thiscase, the gyration via may be formed in an askew or stepwise manner,rather than to be perpendicular to the substrate, in order to connectthe coil strands.

Also, in the present embodiment, the case in which the coil pattern 113has a quadrangular spiral shape overall is taken as an example, but thespiral shape is not limited thereto and the coil pattern 113 may bevariably applied. Namely, the coil pattern 113 may have a circular orpolygonal spiral shape.

In addition, an insulating protective layer (e.g., a resin insulatinglayer (not shown)) may additionally be formed on an upper portion of thecoil pattern 113 in order to protect the coil pattern 113 against theoutside as necessary.

Meanwhile, the contact pad 119 may be formed at one side of thesubstrate 112, i.e., outwardly of the coil pattern 113, in order toelectrically connect the coil pattern 113 to the outside.

Both ends of the coil pattern 113 may be supposed to be electricallyconnected to the contact pad 119, so at least two contact pads 119 maybe provided.

Also, in the present embodiment, the contact pads 119 are disposedoutwardly of the coil pattern 113. Here, although the contact pads 119are disposed outwardly of the coil pattern 113, both ends of the coilpattern 113 in the thin film coil 110 according to the presentembodiment maybe easily connected to the contact pads 119 through theforegoing gyration path and the lead out pattern 117 d.

Also, as shown in FIG. 6, the contact pad 119 according to the presentembodiment may be disposed to be protruded from the substrate 112 havinga quadrangular shape. Thus, when the thin film coil 110 and the magneticunit 120 are coupled, the contact pad 119 is exposed from the magneticunit 120.

Thus, even after the thin film coil 110 according to the presentembodiment is coupled to the magnetic unit 120, the coil pattern 113 andother components (e.g., a battery, a voltage conversion unit, or thelike) may be easily electrically connected.

Meanwhile, in the present embodiment, the case in which the coil strand117 or 118 is formed as a single strand is taken as an example, but thecoil strand 117 or 118 is not limited thereto and the coil strand 117 or118 maybe formed as multiple strands as in another embodiment asdescribed hereinafter.

Also, in the thin film coil 110 according to the exemplary embodiment,the number of the coil strands 117 and 118 which may be formed on onesurface of the substrate 112 may be determined according to the size ofthe substrate 112, i.e., the size of the electronic device.

Namely, when the substrate 112 is formed to have a relatively largesize, a plurality of coil strands, rather than a single strand, may beformed on one surface of the substrate 112 as shown in FIG. 10, and whenthe substrate 112 is formed to have a relatively small size, only thesingle coil strand 117 or 118 as in the present embodiment may be formedon one surface of the substrate 112.

Although not shown, the contactless power reception apparatus 100according to the present embodiment may further include a connectionmember electrically connecting the contact pad 119 of the thin film coil110 to the battery 12 (in FIG. 2) of the electronic device in order toprovide power generated from the coil pattern 113 of the thin film coil110 to the battery 12.

The connection member may be a conductive wire or a thin film circuitboard (e.g., an FPCB) within a wiring pattern formed therein.

In the contactless power reception apparatus 100 according to thepresent embodiment, since the coil pattern 113 is formed on the thinfilm substrate 112, rather than using a wire type coil as in the relatedart, the thin film coil 110 may be formed to be relatively very thin.

Also, the single coil pattern 113 is formed by the plurality of coilstrands 117 and 118 connected in parallel. Thus, the coil pattern 113according to the present embodiment is formed as a pattern on thesubstrate 112, but an effect of using a stranded wire type coil (e.g.,Litz wire) formed by twisting several strands of wire may be achieved.The use of the stranded type coil may significantly reduce loss (e.g.,an AC resistance value, etc.) made by an eddy current, a skin effect, orthe like, at a low frequency.

In this manner, in the contactless power reception apparatus 100according to the present embodiment, although the coil pattern 113 isformed to have a stranded wire form, the thickness of the thin film coil110 may be significantly reduced (e.g., 0.1 mm or smaller), reducing theoverall thickness of the contactless power reception apparatus 100.

In addition, in the contactless power reception apparatus 100 accordingto the present embodiment, the contact pads 119 of the thin film coil110 are all disposed on lateral sides of the substrate 112. Also, anadditional configuration for disposing the contact pads 119 on thelateral side of the substrate 112 is not required. This strength will bedescribed as follows.

Among the contact pads 119 connected to both ends of the coil pattern113, the contact pad 119 connected to the coil pattern 113 wound towardthe interior (i.e., the center) of the coil pattern 113 may be disposedat the inner side of the coil pattern 113, rather than at an outer sidethereof. In this case, the contact pad 119 disposed at the inner side ofthe coil pattern 113 should be electrically connected to the outsidethrough a conductive wire, a connection board (e.g., an FPCB), or thelike.

Also, in order to dispose the contact pads 119 outwardly of the coilpattern 113, a bridge formed of an insulating material maybe formed onthe coil pattern 113 to forma pattern or a multilayer substrate formedby laminating several layers should be used as the substrate 112.

In this case, however, a fabrication time or fabrication costs arerequired to form the bridge on the substrate or fabricate a multilayersubstrate, and the overall thickness of the substrate 112 is increased.

However, in the thin film coil 110 according to the present embodiment,the contact pads 119 may be disposed outwardly of the coil pattern 113without using a multilayer substrate or a bridge. Thus, in comparison tothe foregoing case, a fabrication time or fabrication costs may bereduced and the thickness of the thin film coil 110 or the contactlesspower reception apparatus 100 may be prevented from being increased.

Meanwhile, the configuration of the thin film coil 110 as describedabove may also be applied in the same manner to the contactless powertransmission apparatus 200 provided in the charging device 20. Thus, adetailed description of the contactless power transmission apparatus 200will be omitted.

Hereinafter, a thin film coil according to an exemplary embodiment hasthe same structure as that of the thin film coil (110 in FIG. 6) of theforegoing embodiment, except for a shape of a coil pattern. Thus, thesame reference numerals will be used for the same components, a detaileddescription thereof will be omitted and the shape of the coil patternwill be described in detail.

FIG. 10 is a perspective view schematically showing a thin film coilaccording to another exemplary embodiment.

With reference to FIG. 10, the thin film coil 110 according to thepresent embodiment may include a thin film substrate 112 and the coilpattern 113 formed on the substrate 112, as in the foregoing embodiment.

The coil pattern 113 according to the present embodiment may include aplurality of coil strands 117 a to 117 c disposed in parallel. Theplurality of coil strands 117 a to 117 c are electrically connected tothe same contact pad 119. Accordingly, the respective coil strands 117 ato 117 c are connected in parallel to form a single coil pattern 113.

In the present embodiment, the case in which the coil pattern 113 isformed by three coil strands 117 a to 117 c on one surface of thesubstrate 112 is taken as an example. In this case, the respective coilstrands 117 a to 117 c of the coil pattern 113 are spaced apart fromeach other at a certain interval and disposed to be parallel to eachother.

As in the foregoing embodiment, the coil pattern 113 according to thepresent embodiment includes the lead out pattern 117 d and a pluralityof gyration vias 115. Thus, there is no need to use a multilayersubstrate or a bridge, and the contact pads 119 may be disposedoutwardly of the coil pattern 113 without increasing the thickness ofthe substrate 112, reducing the overall thickness of the thin film coilor the contactless power reception apparatus, shortening a fabricationtime, and reducing fabrication costs.

Meanwhile, in FIG. 10, for example, the lead out pattern 117 d is formedas a single coil strand, but the lead out pattern is not limited theretoand the lead out pattern 117 d may also be formed as a plurality of coilstrands like the other portions of the coil pattern 113.

Also, like the coil strands 117 a to 117 c formed on the upper surfaceof the substrate 112, a plurality of coil strands (not shown) may beformed on a lower surface of the substrate 112. However, the coilstrands are not limited thereto, and only a single coil strand having arelatively large width maybe formed on the lower portion of thesubstrate 112. Namely, the coil strand may have various forms asnecessary as long as the coil strands 117 a to 117 c formed on the uppersurface of the substrate 112 may be electrically connected to the coilstrand(s) of the lower surface of the substrate 112 through the gyrationvia 115.

As described above, the thin film coil and the electronic device havingthe same according to the exemplary embodiments are not limited to theforegoing embodiments and are variably applicable. For example, in theforegoing embodiments, the contact pads of the thin film coil aredisposed in the same direction of the substrate, but the contact padsmay be disposed at both sides of the substrate as necessary. Namely, thecontact pads may be variably applicable.

Also, the thin film coil provided in the contactless power transmissionapparatus of the electronic device is described as an example in theforegoing embodiments.

However, the thin film coil is not limited thereto and the thin filmcoil may be extensively applied to electronic components or electronicdevices, such as a transformer, a motor, or the like, which employ acoil.

As set forth above, according to the exemplary embodiments, since a coilpattern is formed on a thin film substrate, rather than by using a wiretype coil such as that of the related art, the thin film coil may beformed to be relatively very thin.

Also, since the single coil pattern is formed by the plurality of coilstrands connected in parallel, an effect of using a stranded wire typecoil (e.g., Litz wire) formed by twisting several strands of wire may beachieved. The use of the stranded type coil may significantly reduce aloss (e.g., an AC resistance value, etc.) caused by an eddy current, askin effect, or the like, at a low frequency.

Also, in the thin film coil according to the present embodiment, thecontact pads may be all disposed outwardly of the coil pattern withoutusing a multilayer substrate or a bridge. Thus, a fabrication time orfabrication costs of the thin film coil maybe reduced, and the overallthickness of the thin film coil, an electronic device including thesame, or the contactless power reception apparatus may be reduced.

While the present invention has been shown and described in connectionwith the embodiments, it will be apparent to those skilled in the artthat modifications and variations may be made without departing from thespirit and scope of the invention as defined by the appended claims.

What is claimed is:
 1. A thin film coil, comprising: a substrate havinga first surface and a second surface and formed of an insulating layer;a first spiral pattern including a plurality of first coil strandsformed spirally on the first surface of the substrate and having atleast a portion electrically connected in parallel; a second spiralpattern including a plurality of second coil strands formed spirally onthe second surface of the substrate and having at least a portionelectrically connected in parallel, and electrically connected to thefirst spiral pattern; a first contact pad electrically connected to allends disposed outwardly of the plurality of first coil strands; a secondcontact pad electrically connected to all ends disposed inwardly of theplurality of first coil strands; a lead out pattern formed on the firstsurface of the substrate, and leading out of the first spiral patternfrom an end disposed on an inner side of the first spiral pattern; and aplurality of gyration vias passing through the substrate in a positionadjacent to the lead out pattern, and connecting the first spiralpattern and the second spiral pattern.
 2. The thin film coil of claim 1,wherein the first spiral pattern is disconnected and is connected to thesecond spiral pattern through the plurality of gyration vias in theposition adjacent to the lead out pattern.
 3. The thin film coil ofclaim 2, wherein the first spiral pattern and the second spiral patternare connected to each other in parallel.
 4. The thin film coil of claim1, wherein at least a portion of the lead out pattern has a shape inwhich a plurality of strands are connected in parallel.
 5. The thin filmcoil of claim 1, further comprising a conductive connection via disposedon an end disposed on an inner side of the second spiral pattern,wherein an end disposed on an inner side of the first spiral pattern andan end disposed on an inner side of the second spiral pattern areelectrically connected by the conductive connection via.
 6. The thinfilm coil of claim 1, wherein the first contact pad and the secondcontact pad are disposed outwardly of the first spiral pattern.
 7. Awireless power receiving apparatus wirelessly receiving powertransmitted by wireless power transmission apparatus to store the powerin a battery, the wireless power receiving apparatus comprising: asubstrate having a first surface and a second surface and formed of aninsulating layer; a first spiral pattern including a plurality of firstcoil strands formed spirally on the first surface of the substrate andhaving at least a portion electrically connected in parallel; a secondspiral pattern including a plurality of second coil strands formedspirally on the second surface of the substrate and having at least aportion electrically connected in parallel, and electrically connectedto the first spiral pattern; a first contact pad electrically connectedto all ends disposed outwardly of the plurality of first coil strands; asecond contact pad electrically connected to all ends disposed inwardlyof the plurality of first coil strands; a lead out pattern formed on thefirst surface of the substrate, and leading out of the first spiralpattern from an end disposed on an inner side of the first spiralpattern; and a plurality of gyration vias passing through the substratein a position adjacent to the lead out pattern, and connecting the firstspiral pattern and the second spiral pattern.
 8. The wireless powerreceiving apparatus of claim 7, wherein at least a portion of the leadout pattern has a shape in which a plurality of strands are connected inparallel.
 9. An electronic device comprising: a wireless power receivingapparatus; a battery storing power received by the wireless powerreceiving apparatus; and a case to accommodate the wireless powerreceiving apparatus and the battery therein, wherein the wireless powerreceiving apparatus comprises: a substrate having a first surface and asecond surface and formed of an insulating layer; a first spiral patternincluding a plurality of first coil strands formed spirally on the firstsurface of the substrate and having at least a portion electricallyconnected in parallel; a second spiral pattern including a plurality ofsecond coil strands formed spirally on the second surface of thesubstrate and having at least a portion electrically connected inparallel, and electrically connected to the first spiral pattern; afirst contact pad electrically connected to all ends disposed outwardlyof the plurality of first coil strands; a second contact padelectrically connected to all ends disposed inwardly of the plurality offirst coil strands; a lead out pattern formed on the first surface ofthe substrate, and leading out of the first spiral pattern from an enddisposed on an inner side of the first spiral pattern; and a pluralityof gyration vias passing through the substrate in a position adjacent tothe lead out pattern, and connecting the first spiral pattern and thesecond spiral pattern.
 10. The electronic device of claim 9, wherein atleast a portion of the lead out pattern has a shape in which a pluralityof strands are connected in parallel.
 11. A case assembly of a portabledevice wirelessly receiving power, the case assembly comprising: a thinfilm coil; and a case of the portable device disposed on the other sideof the thin film coil, wherein the thin film coil comprises: a substratehaving a first surface and a second surface and formed of an insulatinglayer; a first spiral pattern including a plurality of first coilstrands formed spirally on the first surface of the substrate and havingat least a portion electrically connected in parallel; a second spiralpattern including a plurality of second coil strands formed spirally onthe second surface of the substrate and having at least a portionelectrically connected in parallel, and electrically connected to thefirst spiral pattern; a first contact pad electrically connected to allends disposed outwardly of the plurality of first coil strands; and asecond contact pad electrically connected to all ends disposed inwardlyof the plurality of first coil strands, a lead out pattern formed on thefirst surface of the substrate, and leading out of the first spiralpattern from an end disposed on an inner side of the first spiralpattern; and a plurality of gyration vias passing through the substratein a position adjacent to the lead out pattern, and connecting the firstspiral pattern and the second spiral pattern.
 12. The case assembly ofclaim 11, wherein at least a portion of the lead out pattern has a shapein which a plurality of strands are connected in parallel.